Biochar mitigates Fusarium wilt by regulating the rhizosphere microbial community structure

Area of Science:

• Agricultural Science
• Soil Science
• Microbiology

Background:

• Continuous faba bean cropping degrades soil ecosystems, increasing autotoxins and pathogens, which worsen soilborne diseases.
• Biochar (BC) application shows promise in reshaping soil microbial communities to combat these issues.
• Understanding BC's role in mitigating Fusarium wilt is crucial for sustainable agriculture.

Purpose of the Study:

• To elucidate the rhizosphere microbial mechanisms by which biochar mitigates Fusarium wilt.
• To evaluate the effects of varying wheat straw biochar application rates on soil microbial communities.
• To assess biochar's impact on disease incidence, autotoxic compounds, microbial diversity, and plant defense responses.

Main Methods:

• Wheat straw biochar was applied at rates of 0%, 0.5%, 1%, 1.5%, 2%, and 3% in pot experiments.
• Effects on Fusarium wilt incidence, phenolic acid accumulation, and soil microbial community structure were analyzed.
• Root pathogenesis-related protein (PR) gene expression was assessed following inoculation with biochar-conditioned soils.

Main Results:

• Biochar application reduced the Fusarium wilt disease index by up to 52.11%, with optimal results at 1% application.
• One percent biochar decreased phenolic acids, increased Proteobacteria, and decreased Ascomycota abundance.
• Beneficial bacteria like Bacillus sp. and Sphingomonas sp. increased, while Fusarium commune decreased, alongside upregulated root PR protein expression.

Conclusions:

• One percent wheat straw biochar effectively reshaped the soil microbiome, reducing autotoxins and suppressing Fusarium wilt.
• Biochar application enhances soil health and plant defense mechanisms against soilborne diseases.
• This study highlights biochar as a sustainable strategy for managing Fusarium wilt in continuous cropping systems.